I somehow never understood what square/block is. Tried to understand it again, but still not able to find any grasp while browsing their site. What are they doing?
They are a payments processor, like Shopify. They make physical card readers, with a focus on small retailers, restaurants, nail salons, small time family businesses. Some up-market support. Also e-commerce products that compete more closely with Shopify.
They also build cash app, a competitor to Venmo. They have investment and banking and tax products.
They also have some crypto side projects and own tidal.